Wednesday 22 May 2013 19.30 EDT
First published on Wednesday 22 May 2013 19.30 EDT

In his own mind, Ed Miliband is pretty clear about how he would like to distinguish the Labour party he leads from the Labour party that went before. He aims to be readier than Blair and Brown to challenge the powerful in general, and the economically mighty in particular.

Over three years, we've seen flashes of both halves of that – in, for example, his determination to take Wapping to task over phone hacking, and in his conference speech on predatory capitalism, which initially left pundits scratching their heads, but looked smarter as the months rolled by.

However worthy specific policy ideas – such as using procurement to encourage training, and overhauling reporting rules for listed firms – it is tough to persuade the experts that these things can achieve anything much from the opposition benches, and tougher to persuade voters to do anything but yawn.

The great PR problem with the agenda has been the absence of real-life predators to point to – demons to bring the story to life. A wave of fury over tax avoidance should transform the possibilities; voters who sweat for pay they cannot divert to Luxembourg or Bermuda rage at the antics of the Amazons and Googles who thrive upon their custom.

While Nick Clegg and David Cameron are also manoeuvring to make anti-avoidance their own, the coalition is beset by infighting, and Mr Miliband spots an open goal. He struck at it on Wednesday, by adding aggressive words about Google's aggressive tax practices into a long-planned speech at the firm's Big Tent.

The remaining question, however, is whether Labour – a party that pussyfooted around with avoidance for 13 years – can convince the country it will do better next time. That will have to involve hard and specific commitments to act.

Mr Miliband is making the right noises, talking up comprehensive country-by-country reporting of corporate finances, and also signalling a willingness to act unilaterally if the PM's vaunted efforts at the G8 do not succeed.

Sadly, Ed Balls's policy papers remain overly cautious on the smallprint, replete with talk of "intelligent transparency", which can surely only be something more slippery than transparency plain and simple.

The endless questions on a tax return are tiresome, but – Labour take note – in the end the thing to do is declare on every detail.